Energy of an electron in the ground state of the hydrogen atom is `-2.18 xx 10^(-18) J`. Calculate the ionization enthalpy of atomic hydrogen in terms of `J mol^(-1)`.

Explanation

Ionization enthalpy is the amount of energy required to removed the electron from ground state to infinity.
Energy of electron ground state ` = -2.18 xx 10^(-18) J`
Energy of electron at infinity = 0
Energy required to remove electron ` = - (2.18 ) xx 10^(-18) J = 2.18 xx 10^(-18) J`
Amount of energy required to remove 1 mol of electrons from 1 mol of H atom
` = 2.18 xx 10^(-18) J xx 6.022 xx 10^(23) `per mol
` :. ` Ionization enthalpy of hydrogen
` = 13.130 xx 10^(5) J " mol "^(-1)`
` = 13.13 xx 10^(5) J " mol "^(-1)`
Note: Ionisation enthalpy is always positive.